There is known a hologram recording technique of recording data to be recorded, as an interference pattern, into a hologram recording medium. In one method, light from a light source is spatially-modulated in accordance with the data to be recorded, by using a modulation pattern obtained by combining two-dimensional white and black patterns which are generated in accordance with a predetermined modulation rule, to thereby generate information light, and the recording medium is irradiated with the signal light and reference light The information light and the reference light form the interference pattern on the recording medium, and the interference pattern is recorded into a recording layer of the recording medium. On the other hand, in reproduction, the interference pattern recorded in the recording medium is irradiated with only the reference light, and detection light from the recording medium is detected by a two-dimensional (2D) sensor, to thereby reproduce the data
As in the information recording onto an optical disc or the like, even in the hologram recording, object light and the reference light are focused on the recording medium by using an objective lens or the like. Therefore, in order to accurately perform the information recording and reproduction, addressing control and tracking servo control are required, wherein the addressing control is to preferably recognize a position on the hologram recording medium and the tracking servo control is to control the position of the objective lens with respect to the hologram recording medium. In order to perform the addressing control and the tracking servo control, it is possible to use the hologram recording medium provided with: a hologram recording layer to record therein data; and an address information layer to record therein an address or the like (refer to patent documents 1 and 2). With respect to such a hologram recording medium, it is possible to record the data into the hologram recording medium while preferably performing the addressing control and the tracking servo control or the like, for example, by recording the data into the hologram recording layer with blue laser light and by reading the address or the like recorded in the address information layer with red laser light.    Patent document 1: Japanese Patent Application Laid Open NO. 2005-196826    Patent document 2: Japanese Patent Application Laid Open NO. 2005-71528